Gas mask



0t.11,`193.` TAOLEARY v `.2,132,433

GAS MASK Filed oct. e, 1937 /A/VENTOE 7740 MHS OZ. En@ r Patented Oct-11, 1938 UNITED STATES PATENT oFFicE Gas msx Application October 6, 1937, Serial No. 167,570

2 Claims.

'I'he invention relates to gas masks. It has. for one of its principal objects the provision of means reducing the dead air space in communication with the interior of the mask to a minimum, so that any used air inhaled by the wearer is correspondingly reduced to a minimum. A further object is the provision of means of the character specified applied in an improved manner to the type of mask having the air inlet tubes 0 directed vtoward the lenses for removing condensation, and adapted to assist in directing the inflowing air against the lenses. A still further object is the provision of improved check valve means for the extreme ends of the inlet tubes which provide practically no resistance to the passage of air into the mask, which are of negligible weight, which are reliable in operation and which are easily replaceable. One embodiment of the invention is illustrated in the accompanying drawing, wherein:

Figure l is an elevation of the inner or back side of the mask. Fig. 2 is an enlarged section on the line II-II of Fig. 1. Fig. 3 is a plan view on an yenlarged scale of the check valve disc.

25. And Fig. 4 is an enlarged section through the check valve construction at the end of one of the inlet tubes.

Referring to the drawing, 5 is the bodyof themask, preferably of molded rubber, and provided v with the lenses 6, 6. `Integral with the body of the mask at the lower end, is the neck 1, divided into two passages B and 9 by the wall l0. Extending into the neck 1 is a metal fitting having a pair of branches II and I2 communicating with the passages 8 and 9, the neck and tting being secured together by the metal clamping band i3. The branch I i is connected to the hose Il leading to the canister (not shown), while the branch i 2 carries the rubber iiutter valve I5 for the passage of the exhaled air.

Forming an upward extension of the neck 1, and also integral with the body of the mask and such neck, are a pair of branch tubes- I5, IB which open at their lower ends into the passagel 8. The upper or outlet ends of these tubes terminate adjacent the lower ends of the lenses 6, 6, as indicated in the drawing, and are designed to dischargev over the lenses and promote the rapid removal of condensation, as is well known in the art. The discharge of the incoming air against the lenses is promoted by the check valve discs Il, I l which are hinged for movement at the sides oi the tubes remote from the lenses.

The valve discs Il, I1 are of light, ilexible sheet rubberand are mounted so that they swing up and down freely offering a minimum resistance to the flow of air into the mask. Each disc is slotted at one edge as indicated `at I8 in Fig. 3,

(Cl. 12S-141) and attachment is made to the end oi' the tube by means of the lug i9 (Fig. 4) integral with the wall of the tube, which lug is pushed through the slot Il, so that the head of the lug locks the disc against removal. This attachment is easily ac- 5 complished, as the rubber surrounding the slot i8 is readily stretched to 'permit the passage of the head of the lug. l

The location oi the discs Il at the upper ends of the tubes I6 not only assists in directing the 10 the use oi' tools. i I 20 The construction is capable of some modification without departing from the invention as illustratedin the preferred embodiment thereof. The tubes IB are not necessarily circular in cross section, and in case of a modification in this 25 particular, the shape of the valves would necessarily be changed to ilt the tubes. 'I'he tubes may also discharge at a point other than the bottom of the lenses although the position Lshown is regarded as preferable. use some other material, which has the desired characteristics for the rubber of the valves.

What I claim is:

1. In combination in a gas mask having a body portion and a pair of lenses, an inlet tube hav- 35 ing at its inner end a pair of branch tubes eachy of which has an open discharge end forming a valve seatlying in afplane transverse to a lens and at one end thereof, and a check valve of thin exible sheet material mounted on each seat and 40 hinged thereto at the side of the branch tube remote from the lens so that when the valve swings open it formsa baille directing the incoming air against the lens.

2. In combination in a gas mask having a body 45 portion and a pair of lenses, an inlet tubehavlng at its inner end a pair of branch tubes each of which has an open `discharge end forming a valve seat lying in a plane transverse to a lens and at ,one end thereof, said body portion and 50 tubes being integral and of molded rubber, and a check valve of thin sheet rubber mounted on each seat and hinged thereto at the side of the branch tube remote from the lens so that when the valve swings open it forms a battle directing 55 the incoming air against the lens.

THOMAS A. OLEARY.

It is also possible to 30 

